1. Field of The Invention
The present invention relates to a compact sorter for copy machine, and more particularly to a bin tray transferring apparatus of the sorter capable of preventing the bin trays each having a pair of tray pins from deviation, such as due to outside force, during upward and downward movement thereof by using the driving power of the transfer wheel.
2. Description of The Prior Art
Conventionally, a representative type of known sorter for copy machine is provided with a pair of side plates each having a slot liner extending toward the ejecting section of the copy machine and adapted to guide the movement of bin trays for receiving the separate document distributed from the ejecting section of the copy machine and a transferring member for transferring the bin trays, such as a transfer wheel mounted to the side plate near the inclined middle portion of the slot liner. Thus, the bin trays are transferred up and down one by one by rotation of the transferring member.
An example of the conventional type of tray transferring apparatus, as disclosed in U.S. Pat. Nos. 4,328,963 and 4,332,377, is provided with a wire of which one end is connected to the pin tray of the lowest bin tray, while the other end is connected to the spring disposed at the upper portion of the sorter.
There has been also proposed a known sorter using a drum cam instead of the transfer wheel. For examples, a sorter disclosed in U.S. Pat. No. 4,466,609 is provided with two drum cams and a support frame, and a sorter disclosed in United Kingdom Patent No. 2,168,037 is equipped with an auxiliary bin tray supporter having the same shape as that of the slot liner so that the bin tray can move vertically upwards and downwards upon providing a simultaneous moving of the inner portion of the bin tray, that is a pin tray side, and the outer portion thereof, that is a tap side.
Also, as disclosed in Japanese Patent laid-open publication No. sho 60-232370, a transferring apparatus capable of using support frame in the construction of using the transfer wheel has been proposed. Such type of transferring apparatus have an auxiliary protrusion provided at a part of the outside of the radius of gyration of the transfer wheel and more equipments such as cams and outer springs adapted to drive the transfer wheel. Furthermore, this type of transferring apparatus has a contact surface provided at the bin tray and adapted for contacting with the pin tray during driving the transferring apparatus. The transfer wheel moves in revolution and precipitation at the same time.
Korean Patent Laid-Open Publication No. 91-371 discloses a bin tray transferring apparatus of sorter adopting a method capable of reducing the noises by changing the shape of transfer wheel to have a camming mechanism. Also, as disclosed in Korean Patent Application Nos. 90-855 and 90-16620, which were applied by this applicant, there has been proposed another type of sorter having a slot liner having an inclined middle portion extending from the upper and lower vertical portions of the slot liner toward the ejecting section of the copy machine. In this type of sorter, the bin tray can advance closer to the ejecting section of the copy machine, thereby making it possible to receive and arrange the copies without any auxiliary guiding unit.
On the other hand, the applicant of this invention has proposed a sorter having a transfer wheel provided with three slots, as disclosed in Korean Patent Application No. 90-18264. This sorter carries out a transferring operation for the bin tray during one third cycle of rotation of the transfer wheel as a result of the three slots each arranged at every 120.degree. on the transfer wheel and extending radially inward from a circumference of said transfer wheel, and transfers slowly and upwardly another lower waiting bin tray according to the driving rate of the transfer wheel because the transfer wheel was also provided with involute portions each formed at sections which contacts with the pin tray of the bin tray so that a waiting pin tray could be smoothly and naturally located within the radius of gyration of said transfer wheel. Thus, this type of transfer wheel could be applied to various types of sorters provided with biasing units for urging the bin tray upwardly, said biasing units using a spring, a wire, a rack or a supporting mechanism.
Also, the applicant of this invention proposed another type of bin tray transferring apparatus of a sorter as disclosed in Korean Patent Application No. 91-4036. This type of apparatus is invented for solving a disadvantage of the transfer wheel of the above-mentioned Korean Patent Application No. 90-18264, generation of considerable noise. Therefore, this apparatus is provided with a pair of side plates, first and second transfer wheels each mounted to each said plate, first and second slot liners formed on opposite side plates of the sorter and each having at a portion thereof within the radius of gyration of the transfer wheel an inclined middle portion extending toward an ejecting section of the copy machine. The apparatus also has a pair of racks each engaging with a rack driving member and having a lower portion fixedly connected to the pin tray of a lowest positioned bin tray. In addition, the transfer wheel includes three radial slots, normally formed rounded portions each formed between two slots and having two passages, said passage formed at a surface with which the pin tray of the bin tray contacts. Thus, simultaneously with transferring the bin trays one by one by means of the rotational power of the transfer wheel the apparatus drives the racks to move upwards and downwards so as to cause the whole bin trays to move upwards and downwards. However, almost the known sorters having the conventional bin transferring apparatus has disadvantage in that the bin tray transferring apparatus is provided with no device for preventing the bin trays from deviation during upward and downward movement thereof along the slot liners of the side plates, thereby causing the bin trays to deviate from the sorter such as to outside force. In an effort for solving the above-mentioned disadvantage, some of known sorters include a bin tray transferring apparatus provided with an auxiliary weight bar mounted at the upper portion of the sorter so as to simply weighting the tray pins of bin trays downwards by means of its own weight. However, this type of bin tray transferring apparatus has a considerable weight, resulting in increasing the load imposed on the bin tray as the bin tray is transferred upwards by the transferring apparatus. Also, the weight bar has a simple construction for providing the downward weighting function thereof for the bin trays, so that it has no device for preventing the pin tray of the bin tray from ascending in the slot liner due to an outside force imposed on the bin tray. Thus, this type of weight bar has a disadvantage in that one of the opposite tray pins of the bin tray in movement often ascends in the slot liner due to the outside force so that the transfer wheel picks up only one pin tray disposed in its place, while the other pin tray, ascending pin tray, can not be picked up by the transfer wheel, thereby causing a trouble of the sorter.
In an effort for solving the above disadvantage of weight bar, a sorter provided with another type of weight bar has been proposed by the RICOH company. This type of sorter is provided with a pair of auxiliary hooks provided at the side plates, respectively, each hook upwardly disposed between the lift shaft provided at the lower end of the rack and a shaft provided at the upper portion of the uppermost bin tray and adapted for supporting the bin trays so as to prevent the bin tray from deviation. However, this type of sorter must be provided, at a vertical supporting distance by means of the hook, with a vertical space taking account of a thick of a plurality of copies (about 100 copies) which is to be received by the uppermost bin tray, so that the hook can not sufficiently weight the tray pins downwards due to the space taking account of the thick of the copies. Hence, this type of sorter only prevents the deviation of the bin trays from slot liner of the sorter, but it can not solve the above-mentioned disadvantage of the weight bar. Furthermore, this sorter has to be provided at the opposite upper portions of the sorter with a pair of auxiliary shafts for supporting the upper end of the hooks.